The present invention relates to a side rail disposed above the deck on one lateral side for preventing the bedding such as a bed quilt and a user such as a patient from falling, particularly a liftable side rail, which can be lifted and lowered between the service position above the deck and the stored position below the deck.
The conventional side rails to be disposed above the deck on one lateral side of a lying table such as a bed or stretcher include, as described later, a detachable side rail consisting of a side rail proper and columns which are inserted into the fitting holes formed in a lateral side of the deck, for supporting the side rail proper in its service condition, and a liftable side rail in which a side rail proper is supported liftably by any proper lifting mechanism, to be used at a lifted position and to stored at a lowered position for avoiding any disturbance by the top of the side rail proper. They also include an full side rail to cover an entire lateral side of a lying table, and a partial side rail to cover an entire lateral side of a lying table in combination with other side rails, usually another side rail.
As an example of lying tables, medical beds are being specified in dimensions of respective portions by standards to allow their safe use. For example, for partial side rails, for example, IEC specifies the dimensions of respective portions as described below in reference to FIG. 6.
The components of FIG. 6 will be explained at first. Symbol 1 denotes the deck of a bed, and the deck 1 is liftably supported above a base 2 by any proper link mechanism 3, and can be driven to be lifted and lowered by a drive mechanism not illustrated.
Symbol 4 denotes a partial side rail which is supported by any proper support mechanism at one lateral side of the deck 1 in its service condition. Two such partial side rails 4 are installed side by side, to cover the entire lateral side of the deck 1. Each of the partial side rails consists of a side rail proper 5 and columns 6 which are inserted into the fitting holes (not illustrated) formed in a lateral side of the deck 1. As for other illustrated components, symbol 7 denotes a mattress placed on the deck 1; 8, a head board; and 9, a foot board.
The specified dimensions of the respective portions shown in FIG. 6 are described below.
The dimension indicated by A shows the dimension of each closed space formed in the side rail proper 5 of the side rail 4, when the side rail proper 5 is a lattice with spaces in it. The dimension of each space is specified to be 120 mm or less, to prevent that the head of the user enters into the space.
The dimension indicated by D is the dimension of the gap between the side rails proper 5 of the adjacent side rails 4, or the dimension of the gap between the side rail proper 5 on the head board side and the head board 8 or between the side rail proper 5 on the foot board side and the foot board 9. The dimension of any of the gaps is specified to be 60 mm or less to prevent that the neck of the user enters into the gap, or to be 235 mm or more, to prevent that the head is caught in the gap.
The dimension indicated by F is the dimension of the gap between the bottoms of the side rails proper 5 and the deck 1 when there is an open space above the gap. The dimension of the gap is specified to be 120 mm or less to prevent that the head enters into the gap when the neck cannot enter into the above opening, or to be 60 mm or less to prevent that the neck goes into the gap below the side rails proper 5 when the neck can enter into the above opening.
G1 and G2 indicate the horizontal lengths of the side rails proper 5 of the respective side rails 4, and are specified to satisfy a formula of G1+G2 greater than L/2, where L is the total length L of the deck 1.
The dimension indicated by H is the height of the side rails proper 5 of the side rails 4 above the mattress, i.e., the dimension between the upper surface of the mattress 8 and the tops of the side rails 4, and is specified to be 220 mm or more.
The dimensions of respective portions of the partial side rails described above are applied also when liftable side rails proper are used at a lifted position.
A conventional example of liftable side rails, particularly partial side rails is described below in reference to FIG. 7.
In FIG. 7, symbol 11 generally denotes a bed equipped with liftable side rails. In this drawing, the detailed structure of the bed is not illustrated, and some components only are indicated by two-dot-dash lines.
Symbol 12 denotes a deck to have a mattress (not illustrated) placed on it, and the deck 12 is divided into four deck portions, i.e., four deck portions 12a, 12b, 12c and 12d respectively corresponding to the back, waist, thigh and legs of the user. They are respectively connected to allow pivotal rotation. The deck 12 consisting of these deck portions is supported above a deck support frame 13. For example, the deck portion 12b is stationarily supported on the deck support frame 13. The deck portions 12a and 12c are pivotally rotatably connected with the deck portion 12b, and pivotally rotatably and liftably supported respectively by proper drive mechanisms (not illustrated). Said support mechanism and drive mechanisms are not illustrated, since they are well-known.
The deck support frame 13 is supported by any appropriate support mechanism on the floor 15 of a room, etc. The support mechanism is not illustrated. For example, the deck support frame 13 can be supported at a predetermined height by stands with casters or can be liftably supported by a lifting link mechanism above a base as shown in FIG. 6. In FIG. 7, symbol 17 denotes a head board, and 18, a foot board.
On the head board 17 side and the foot board 18 side of the deck support frame 13, pairs of support arms 19a and 19b are supported pivotally rotatably around the rotary shafts extending in the transverse direction of the bed. At the tips of the pairs of support arms 19a and 19b, side rails proper 20a and 20b are pivotally rotatably connected, to form parallel motion link mechanisms. The support arms 19a and 19b can also be pivotally rotatably supported on the deck portions 12a, 12c, etc., not on the deck support frame 13.
In the above constitution, the side rails proper 20a and 20b are lifted and lowered by the pivotally rotational motion of the support arms 19a and 19b in parallel along the pivotally rotational loci. The condition that they are held at a lowered position is the stored condition, and the condition that they are held at a lifted position indicated by one-dot-dash lines is the service condition. FIG. 7 shows the side rail proper 20a on the head board 17 side in its service condition, and the side rail proper 20b on the foot board 18 side in its stored condition. The holding mechanism for the service condition and the stored condition is not illustrated, and any proper mechanism using, for example, stopper pins as described later can be used.
These side rails proper 20a and 20b are constituted to satisfy the above mentioned standard dimensions in their service condition. For example, the dimension indicated by b in the drawing corresponds to the dimension of A in the above mentioned standard. According to the standard, b must be 120 mm or less, to prevent that the head of the user does not enter into the gap.
As described above, the liftable side rails, the side rails proper 20a and 20b of which are liftably supported by a lifting mechanism in the service condition at the lifted service position and also in the stored condition at the lowered stored position, must conform to the standard dimensions as described above in the service condition. However, also in the stored condition, there are desirable dimensions in view of convenience.
That is, in the use of the bed shown in FIG. 7, when the side rails proper 20a and 20b are held at the stored position, it can happen that an attendant nurses the user such as a patient lying on the bed, or that the table plate of a movable bed side table is moved and located above the bed. In the former case, it can happen that the attendant inserts his/her legs into the gap formed between the bottoms of the side rails proper 20a and 20b in the stored condition and the floor surface 15 of the sickroom, etc., and in the latter case, the base of the bed side table is moved inside the gap. So, it is desirable that the gap d is larger.
On the other hand, recently there is a tendency to keep the height of the bed deck 12 low, because of various advantages that the user such as a patient can easily get on and off the bed deck 12 and sit at the edge of the deck 12 and that the attendant can more easily nurse if the bed is low in deck height.
In the liftable side rails, the side rails proper 20a and 20b of which can be lifted and lowered in parallel by the pivotal rotation of the support arms 19a and 19b, it is a contradictory challenge to keep the height of the bed deck 12 low, while keeping the distance d between the bottoms of the side rails proper 20a and 20b and the floor surface 15 large.
For example, FIG. 8 shows an attempt to keep the distance d between the bottoms of the side rails proper 20a and 20b and the floor surface 15 large in the bed of FIG. 7.
In the bed of FIG. 8, the vertical height c of the side rails proper 20a and 20b is shorter than that of the side rails proper 20a and 20b of FIG. 7, to keep the distance d between the bottoms of the side rails proper 20a and 20b and the floor surface 15 large, while keeping the distance e between the floor surface 15 and the deck 12 and the distance a between the deck 12 and the tops of the side rails proper 20a and 20b, i.e., the height of the side rails proper 20a and 20b above the deck equal to those of the bed of FIG. 7.
If the vertical height c of the side rails proper 20a and 20b are kept smaller like this, the distance d between the bottoms of the side rails proper 20a and 20b and the floor surface 15 can be kept larger by that. However, in this case, the dimension indicated by b in the drawing becomes large, and there arises a possibility that the dimension indicated by A in the above mentioned standard may not be satisfied.
So, hitherto, these dimensions are set considering the above mentioned contradictory challenge, and it is very difficult to keep the distance d between the bottoms of the side rails proper 20a and 20b and the floor surface 15 large while satisfying the respective standard values of the side rails proper.
This invention has been conceived in view of the above. The object of this invention is to provide a liftable side rail, the side rail proper of which can be lifted and lowered by the pivotal rotation of support arms along the pivotally rotational loci, characterized by allowing the standard values of respective dimensions of the side rail proper to be satisfied, while allowing the bed deck height low and allowing the distance between the bottom of the side rail proper and the floor surface to be kept large at the stored position.
This object can be achieved by a liftable side rail for a lying table such as a bed, comprising a side rail proper, being pivotally rotatably connected with a pair of support arms pivotally rotatably supported at side rail installation points of the lying table such as a bed, to be supported in such a manner that the side rail proper may be lifted and lowered by the pivotally rotational motion of these support arms along the pivotally rotational loci between an upper service position and a lower stored position, and each of the support arms, having protrusions functioning as auxiliary side rail members on both sides of the straight line connecting said installation point and the connection point with the side rail proper.
In the liftable side rail of this invention, each of the support arms can have a parallelogrammic frame provided on the upper side, and the ends of the shorter diagonal of the frame can correspond to the connection point with the side rail proper and the installation point, while the ends of the longer diagonal of the frame can define the protrusions.
Furthermore, in the liftable side rail of this invention, each of the support arms can be a plate with a parallelogrammic portion on the upper side, and the ends of the shorter diagonal of the plate can correspond to the connection point with the side rail proper and the installation point, while the ends of the longer diagonal of the plate can define the protrusions.
Moreover, in the liftable side rail of this invention, each of the support arms can have frame halves on both side of a straight arm portion.
In these constitution, when the side rail is held at the lower stored position, the protrusions provided for the support arms are placed along the side rail proper without protruding above and below. So, the tops and bottoms of the protrusions do not constitute any obstruction. Therefore, even if the lying table is low in the height of the deck, the distance between the bottom of the side rail proper and the floor surface can be kept large.